2B0B
Moderate2B0B — NOx Sensor: Binary Lambda Signal
Description
What This Code Means
2B0B belongs to the EGR / DPF / SCR system code group and points to a fault in the binary lambda measurement of the nitrogen oxide (NOx) sensor. The NOx sensor works on a two-stage measurement: the first stage determines oxygen concentration (lambda), the second determines NOx concentration. Code 2B0B logs a failure in the first, binary part of the lambda measurement.
This code is analogous to 2AF6 — both relate to the same measurement circuit. Severity is rated as moderate.
Symptoms
Symptoms
- Check Engine Light comes on;
- poor fuel economy.
Causes and fixes
Diagnosis and Repair
- Check the NOx sensor readings with INPA. Compare them against expected values and decide on the sensor's condition.
- If the sensor is faulty, replace the NOx sensor.
Possible secondary damage
Secondary Problems
- incorrect lambda readings from the sensor can lead to improper fuel control, meaning the control unit will base the mixture on faulty data.